Machine for trimming the finger plate on a piano key



March 6, 1951 H. D. OSLUND 2,544,175

MACHINE FOR TRIMMING THE FINGER PLATE on A PIANO KEY Filed April 2, 1948 3 Sheets-Sheet 1 I N VEN TOR.

7M; 0 os/m/ BY March 6, 1951 os D 2,544,175

MACHINE FOR TRIMMING FINGER PLATE ON A PIANO KEY Filed April 2, 194a .s Sheets-Sheet 2 c 5 7 :72 24 4 o l /iii ,wom wq March 6, 1951 H'. D. OSLUND 2,544,175

MACHINE FOR TRIMMING THE FINGER PLATE ON A PIANO KEY V Filed April 2, 1948 3 Sheets-Sheet 5 7/- E INVENTOR. 131:; flenen Os/zmJ Patented Mar. 6, 1951 MACHINE FOR. :rnnmvmwo THE mesa PLATEHQNQA PIANO KEY Herbertn'Oslund, Minneapolis P ApplicationvApril'it,1948,;Serial-No. 18,575- I 11 Claims. 1

present invention in machines for trimming .finger plates on piano keys.

It is well known that finger plates to be applied; to piano keys, as replacements, are usually madeof a compositionrepresenting ivory and are of a size somewhat-larger than the finished product; and hence must beitrimmed to the desired size after being applied to piano keys.

- At present, the method of trimming finger plates on piano keys vis a crude, slow and tedious process in which the greater portion of the surplus; stock is removed in a manner that leaves theedge portions of the finger .aplates in a very rough state and which are finally brought to a finished state by means of a rasp while the piano key is; held inavise.

.The principal object of this invention-j 1s to provide'anovel machine by the :use of which} the finger plates on a full set of piano keys may be speedily and. accurately'cut toan exact size.

A further object of this invention is to provide a machine for trimming" finger plates onpiano keys, by the use of which. an operator does not have to change his position; hence saving considerable time in the trimming processx l Other objects of this invention will be apparent from the following description and, the accompanying drawings. i

To the above end, generally stated, the inven-. tion consists ofthe' novel devices and combinaj-z tion of devices hereinafter described and defined inthe claims. 7 p I .In the accompanying drawings, which illustrate the invention, like characters indicate'lik parts throughout the several views. Referring to the drawings; j "Fig. l is a plan view of the improved'machine; .Fig. 2 is a fragmentary view corresponding. to Fig. 1 and further showing, by means of broken lines, two positions of a piano key in which cuts are made in the'longitudinal" edge portions ofthe finger plate on said piano key; Fig. 3 is a fragmentary perspectiv view of a piano key in which cuts are made in the longitudinal edge portions of its finger plate when said-piano key is positioned in the machine as showninFig.'2;j Fig. 4 is a view partly in elevation and partly in section taken on the line' 4-4. of Fig. 1, and

also showing by means of broken lines a piano key in which the outer end portion of its finger plate is to be trimmed; i Fig. 5 is a fragmentary perspective view of a r se? leei whi h. t e. We? 2 .9 PQ Ti PQ 9 i relates to improvements" 4 (oil 1445-2) finger plate has been'trimmed by positioning said} piano key in the machine, as shown in Fig. .4;

Fig. 6 is a view principally in transverse yer-.1 tical section taken-on the line 6-6 of Fig. 4';

vFig.7 is a fragmentary bottom plan view of 'a' piano key and also showing, by means of broken lines, the portions of the finger plate removed by trimming;

Fig. 8 is a perspective view of the inner supporting block; Fig. 9vis a view principally in transverse section taken on the line 9--9 of Fig. 4;

Fig. 10Tis a view principally in section taken on'theline Ill-400i Fig.9; v I

Fig'l'll is a fragmentary plan view of the table and alsoshowing', by means of broken lines, a fragmentv of a .piano key in' a. position in which one of the longitudinal edge portions of its finger plateis to be trin'iinedfj f I Fig; 12 is aview corresponding to Fig. 11; with the exception that the spacer is closed and the. piano key removedtoa position in whichthe' front end portion of the finger plate is-to be trimmed; and p Fig. 13 is a view corresponding to Fig. 11, but showing the piano key positioned for the second cut to complete the trimming of the respective longitudinal edge portion of the finger plate. j-

The numeral 14 indicates a square base having at its corners short supporting legs l5. A rela-.

tively large circulartoothed cutter I6 is mounted on the right-hand'end portion of an arbor l see Fig. 4, and a relatively small circular toothed; cutter I8 is mounted on the other end portion of said arbor. The arbor l1 is-mo'unted in a pair of upstanding bearings 19, between the cutters l6 and I8 and integralwith the base l4.- A'table 20 overlies the "small cutter l8, and is closely positioned to the largecutter l6; Integral with.;the' table 20 is a'wide downwardlyandout; wardly inclined hinge member 2|, the lower-edge portionoi which terminates in a round member 22'. vThe end portions of the member 22 extend outwardly of said hinge member and have formed therein conical seats 23. This member 22 extends between apair of upstandingbearings 24 on. the base l4 and a pair of axially aligned hingeipins 2'5 having screw-threaded engagement with the bearings 24 through which they extend. These hinge pins 25. have conical ends 26 that extend into the seats ,23 in the ends of the member22. Lock nuts 21- on the outer end portions of the hinge pins 25 impinge the bearings 24 and hold said hinge pins where adjusted. Obviously, by adiustingthe hinge pins 25 in the bearings 24,

the table 29 may be adjusted toward or from the plane of the cutter I6. The hinge member 2| afiords a guard for the cutters l6 and I8 and a second guard 28 for said cutters is a sheet metal plate attached to the opposite edge portion of the table 20 from the hinge member 2| and extends outwardly and downwardly from said table. This guard 28 has a narrow upwardly projecting curved extension 29 that overlies the cutter l6 and a long depending flange 30 that overlaps said cutter outwardly thereof.

The table 20 is yieldingly held in a raised position as shown in Fig. 9, by a coiled spring 3| encircling a post 32 secured to the :base l4 and ex tending through a hole 33, Fig. 2, in the hinge member 2 I. Applied to the post 32, outwardly of the hinge member 2|, is a felt washer 34 and a 4 1 the stop block 52 on the other side of said guide plate. The head of the screw 54 impinges the stopblock 52 and said screw 54, when tightened, draws the prongs of said stop block 52 into frictional engagement with the guide plate 45 and holds said stop block where adjusted. In the face of the stop block 52 is a recess 52.

A spacer 51, in the form of a flat plate, is hinged at 58 to the block 43" for swinging movement into a position in which it bears against the outer end of said block, see Fig. 12. The two cotter pin 36. When the table 2| is manually de-' pressed, to bring the work into engagement with either of the cutters [6-48, it engages an adjustable stop 31 that positions the table relative to the cutters i6 and I8. The small cutter 6, when the table 20 is held depressed, works through a slot 38 in the table 20. The adjustable stop 31, as shown, is a long upright machine screw having threaded engagement with an extension 39 on one of the bearings IS. A lock nut 40 on the stop 31 impinges the bearing extension 39 and holds said stop where adjusted.

On the table 20 are two endwise spaced'supporting blocks 42 and. These blocks 42 and 43 are per endicular to the plane of the large cutter l6 and formed therein is a channel .44. Extending longitudinally through the channel '44, at the transverse center thereof. is a flat guide plate 45 that projects materially outwardly of the large cutter l6. 1ft is important to note that the guide plate 45, Fig. 4, extends above the blocks 42' and 43. The guide plate 45 has in its lower longitudinal edge portion a wide notch 46 into which the block 42 extends. Said guide plate 45, at the notch 46, extends into grooves 41, see Fig. 8, in the end portions of the :block 42 with a pressed fit that rigidly connects the block 42 and the guide plate 45. The guide plate 45 is reduced in width at its rear lower edge portion and loosely rests on the bottom of the channel 44.

On the bottoms of blocks 42 and 43 are flat two-part rib 48 that extends into a channel 49 in the table 20 and holds the blocks 42 and 43 for straight-line sliding movement on the table 20 toward or from the plane of the large cutter I6. Each block 42-43 is secured to the table 20, where adjusted, by a set screw 50 that extends through the channel 49, has threaded engagement with the respective blocks 42-43 and with its head impinging the under side of the table 20.

The large cutter I6 works in a deep notch 5| in the under longitudinal edge portion of the guide plate 45. The block 42, at its outer end, is recessed at 42 for the cutter I5 and said block, above this recess, is notched at 42 to aiford clearance for the cutter l6 when the table2|| is held depressed.

Mounted on the outer end portion of the guide plate 45 is an adjustable stop block 52 having in its underside a deep groove 53 into which the guide plate 45 extends with a close working fit. The stop block 52 rests on the guide plate 45, for sliding adjustment toward or from the large cutter IS. A screw 54 extends loosely through a bore 55 in the stop block 52 onone side of the guide guide plate and has threaded engagemeht'with corner portions of the outer block 43 are notched to afford stop shoulders 59 and 60. It is important to note that the block 43, at its rear end portion, is spaced above the table 20as indicated at 43 for the passage of the finger plate of a piano key thereunder.

I The arbor I! is driven by a V belt 6| that runs over a V pulley 62 on said arbor and a like pulley on the armature shaft of an electric motor, not shown. a

The upper edges-of a trimmed finger piece on a piano key are slightly beveled by a file 63, shown by broken lines in Fig. 4. This file 63 is leleasably held in a laterally inclined position in a laterally oblique channel 64 in a rectangular member 65 that affords a support on which the finger plate on a piano key rests, face down, while having its sharp trimmed edge removed by the file 63. The member 65 has atone side a horiz'ontal flange 66 spaced below the top'ofsaid member, resting on thebase l4 and secured there-'; to by a pair of machine screws .61. A set screw. fidabove the fiangeBB has threaded engagementwith the member 65, impinges the file 63 and holds the same pressed against the opposite side of the channel 64.

In the drawings is shown, by means of full and dinal edge portions thereof project outwardly of the head 10 and body of the piano key 69.

Operation I I When the machine is being operated, the operator stands in front of the guard l8, Fig. 1.

Normally, the table, 20 is yieldingly held in a raised position above the cutters. 6 and [8 so that there is no cutting action thereby, as shown in Fig. 4. The table 29 in the other views is shown depressed.

The first operation in trimming the finger plate 72 is to transversely out said plate at its longitudinal edge portions at the shoulders .TI on the head 10, as indicated at 13, in Fig. 3. To make these cuts, the piano key 69 is laid fiatwise on the blocks 42 and 43 with the finger plate 12 ex tending edgewise'into the channel 44 with its face pressed against the adjacent side of the guide plate 45 and with the outerend portion of the finger plate 12 extending into the notch 52a, Figs. 1 and 2, and with the. outer end of the head ID of the piano key 69 in contact with the stop block 52. The adjustment of the stop block 52 on the guide plate 45 endwise positions the piano-key 69 with its shoulders H- in the plane of the outer made at said shoulders. Whilethe piano key 69' is held by the operator in the position above dew scribed, he depresses the table 2llto bring the lower edge portion of the finger plate I2 intocontact with the cutter IE to make one of the cuts Next, the operator releases the depressed table 20, lifts the piano key 69 from the blocks 42 and 43, turns the same about its longitudinal axis to edgewise reverse the finger plate I2 and again lays said key on the blocks 42 and 43 with the finger plate :2 extending into the channel 44 with its face against the opposite side of the guide 45 from the first position of the piano key 69 .and with the end of the keyhead I against the stop block 52. The table 2!] is again depressed to bring the lower edge portion of the finger plate I2 into contact with the cutter Hi to make the second cut $3 in said finger plate.

The next operation of the machine is to trim the outer end portion of the finger plate I2. The first step in this operation is to close the spacer 51 against the rear end of the block 43 and place the piano key 59 with its finger plate I2 extending under the rear end portion 43' of the block 43 and with spacer 5? the outer end of the head H1 in contact with spacer 51 the rear end of said block. While the operator holds the piano key 69 in this position, he depresses the table 20 which projects the cutter l8 through the slot 33 and cuts the surplus stock from the finger plate I2. The purpose of the spacer 51 is to position the piano key 69 so as to leave the outer end of the finger plate I2 projecting slightly outwardly of the outer end of the piano key head I0 a distance the equivalent of the thickness of the spacer 51.

The last and final operation of the machine is to trim the longitudinal edge portions of the finger plate I2 at the sides of the body of the piano key 69 and its head IE. The first step in this operation is to pivotally move the spacer 51 away from the end of the block 43, turn the piano key 69 parallel to the cutter is and away from the operator with the face of the finger plate I2 resting on the table 26 and with the piano key head If! in contact with the rear end of the block 43. Next, the operator depresses the table 2|] to project the cutter 18 through the slot 38 and moves the piano key 69 away from himself to feed the finger plate I2 to said cutter. This cut extends from the outer end of thefinger plate I2 to the respective cut '33 and at the completion thereof positions the head is beyond the block 43 and releases the depressed table 29.

Next, the operator moves the piano key laterally to position the body thereof against the block 43 and with the respective shoulders II on the head to in contact with the stop shoulder 59. The operator now depresses the table 29 to again project the cutter I8 through the slot 33 to make the initial cut in the finger plate 12 at the adjacent transverse cut IS. The piano key 69 is now moved endwise away from the operator to cut the surplus stock at the respective side of. the piano key body from the finger plate I2. At the completion of the out, the operator releases the depressed table 2!]. r

The operator now endwise reverses the piano key 69 and the other side of the finger plate I2 is trimmed by first placing the body of the piano key 69 against the block 43. He then depresses the table 26 and moves the piano key 63 away from himself until the respective shoulders H engage the stop shoulder 60- and the cut is' stopped at the adjacent transverse cut I3. Next,

the piano key 69 is moved laterally away from the block section 43 and the respective side of the head 10 is placed against said block section. Finally, the operator further moves the piano key 69 away from himself to feed the finger plate -12 to the cutter I8 and cut the same at the side of said head.

From what has been said, it will be understood that the machine described is capable of modifications as to details of construction and arrangement within the scope of the invention herein disclosed and claimed.

What I claim is: I

-l. In a device of the class described, a base, a rotary cutter on the base, a table overlying the base, means yieldin'gly holding the table in a raised position, means on the table for support-.

ing a piano key having a finger plate to betrimmed, and a two sided guiding means fixed on the'table perpendicular thereto and on a radial line extending from the axis of the cutter for positioning the finger plate edgewise transversely over the cutter said supporting means being on each side of the guiding means and spaced outwardly therefrom.

2. The structure defined in claim 1, further including an adjustable stop for endwise positioning the piano key relative to the cutter.

3. In a device of the class described, a base, a rotary cutter on the base, a table overlying the base, means yieldingly holding the table in a raised position, a two-sided guide on the table perpendicular to the plane thereof and on a radial line extending from the axis of the cutter, and means on the table for supporting a piano key having a finger plate to be trimmed with the face of the finger plate in contact with one side of the guide and held thereby edgewise transversely over the cutter.

4. The structure defined in claim 3, further including an adjustable stop for endwise positioning the piano key relative to the cutter.

5. In a device of the class described, a base, a rotary cutter on the base, a table overlying the base, means yieldingly holding the table in a raised position, a fixed supporting block on the table for a piano key having a finger plate to be trimmed, said block having therein a channel extending perpendicular to the plane of the cutter, and a fixed two sided guide plate extending longitudinally through its channel at the transverse center and spaced from the sides thereof.

6. The structure defined in claim 5, further including an adjustable stop block slidably mounted on the guide plate for endwise positioning the piano key relative to the cutter.

7. In a device of the class described, a base, a, rotary cutter on the base, a table overlying the base, yielding means holding the table in a raised position, a pair of endwise spaced inner and outer blocks slidably mounted on the table for independent adjustments relative'to the plane of the cutter, means for independently holding the blocks where adjusted, a channel in the blocks perpendicular to the plane of the cutter, a long vertically disposed guide plate extending longitudinally through the channel at the transverse center thereof, said guide plate having in its lower edge portion a deep notch into which the inner block extends, said inner block having grooves into which the edge portions of the guide plate at the notch extend and connect the inner block and the guide plate for common adjust- -ment;r.e1ative :to the plane of the cutter, .saidguide plate extending loosely into the channel in the uter block, and an adjustable stop block on the guide plate.

18.. The structure defined in claim 7 in which the stop block has in its face a recess for receiving the end portion of the finger plate on a piano key endwise engaging the stop block.

9. The structure defined in claim 7 in which the stop block has in its under side a groove into which the uide plate extends and further including means for frictionally clamping the stop block onto the guide plate.

10. In a device of the class described, a base, :a rotary cutter on the base, a table overlying the base and having-an integral, lateral and offset extension pivoted to the base to turn about a horizontal axis, fixed guidin means on the table perpendicular to the plan thereof and on a radial line extending from the axis of the cutter for positioning the finger plate on a piano key edgewise transversely over the cutter, and yielding means holding the table in a raised position.

11. The structure defined :in claim 10, further. including means for adjusting the hinge member, to adjust the table transversely of the plane of the cutter.

HERBERT D. OSLUND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

